Sarcoma - Malignant tumour of the connective and supporting tissue

Sarcomas account for less than 1% of all malignant tumours in adults, but about 10-15% of solid tumours in children.They can occur in almost any part of the body, but most commonly in the extremities, abdomen or soft tissue.

Sarcomas often cause few symptoms in the early stages, which makes diagnosis difficult. Typical signs can be painless swelling or lumps in the soft tissue or bone area. As the disease progresses, pain, restricted movement or weight loss may occur. The diagnosis is made using imaging procedures such as MRI, CT or X-ray as well as a tissue sample (biopsy) to determine the type of tumour. The exact causes of sarcomas are not fully understood, but genetic factors, radiation exposure, chemical noxae (harmful substances) and certain pre-existing conditions play a role. Certain hereditary diseases such as Li-Fraumeni syndrome or neurofibromatosis increase the risk of developing sarcoma.

Direct prevention of sarcoma is not possible, but some measures can reduce the general risk of cancer. Avoiding exposure to radiation and carcinogenic chemicals, an anti-inflammatory diet with antioxidants, omega-3 fatty acids, vitamin D, zinc and selenium and regular exercise all contribute to cell health. Spermidine could also play a role here. Spermidine is a natural polyamine found in foods such as wheat germ, soya beans and mushrooms and plays a central role in autophagy - a cellular self-cleaning process in which damaged or faulty cell components are broken down and recycled. Since cancer often originates from defective cells, the promotion of autophagy by spermidine could help to eliminate potentially dangerous cells at an early stage. In addition, spermidine has anti-inflammatory and antioxidant properties, which could help reduce cell stress and lower the overall risk of cancer. In addition, people with a genetic predisposition should have regular check-ups to detect possible changes at an early stage.

Classification

Sarcomas are roughly divided into two main groups:

• Soft tissue sarcomas (e.g. liposarcoma, leiomyosarcoma, synovial sarcoma, angiosarcoma)
  
• Bone sarcomas (e.g. osteosarcoma, Ewing's sarcoma, chondrosarcoma)
  

Symptoms

The symptoms are often non-specific and depend on the localisation. Possible symptoms:

• Painless, growing swelling or lump
  
• Pain on pressure or movement in a deep position
  
• Impairment of neighbouring structures (e.g. nerves, organs, vessels)
  
• Late: pain, weight loss, fatigue, fever
  

Causes and risk factors

The exact causes are often unclear. Possible influencing factors:

• Genetic mutations or syndromes (e.g. Li-Fraumeni syndrome, neurofibromatosis type 1)
  
• Ionising radiation (e.g. after cancer treatment)
  
• Chronic inflammation or tissue damage
  
• Exposure to certain chemicals (e.g. vinyl chloride)
  

Diagnostics

The clarification is interdisciplinary and includes:

• Physical examination and imaging (MRI, CT, X-ray, PET-CT if necessary)
  
• Biopsy for histological confirmation
  
• Staging (to detect metastases, especially in the lungs and liver)
  

Therapy

Treatment depends on the type, location, stage and molecular biological characteristics of the tumour:

• Surgical removal with the widest possible safety distance
  
• Radiation therapy for local tumour control
  
• Chemotherapy (especially for paediatric sarcomas or aggressive subtypes)
  
• Targeted therapy and immunotherapy (e.g. for GIST, CD13-positive tumours)
  
• Study-based therapies such as in the TRAPTRAP trial, which is testing innovative combinations with fusion proteins such as tTF-NGR to specifically interrupt tumour supply
  

Prognosis

The prognosis depends heavily on the tumour type, the stage at diagnosis, resectability and response to therapy. If detected early, the chances of recovery are good, but the prognosis deteriorates considerably with advanced metastasis.

• Fletcher, C. D. et al (2020). ""WHO Classification of Soft Tissue and Bone Tumours.""
  
• German Sarcoma Foundation (2023). ""Guide for patients with sarcomas.""
  
• Mesters, R. et al (2022). ""TRAPTRAP trial: Targeted tumour vessel infarction in soft tissue sarcoma.""